1. The Field of the Invention
Embodiments of the invention relate generally to the field of data transmission in communication networks. More specifically, embodiments of the present invention relate to devices and systems for collecting physical layer data in communication networks.
2. The Relevant Technology
Modern day communication is, in large part, accomplished by transmitting and receiving large amounts of digital data. Digital data signals can be used to transmit information such as database information, financial information, personal and business information, and the like. In addition, digital data signals can be used to transmit voice, video, images etc.
Typically, data transmission in such networks is implemented by way of a communication module, such as a transceiver or transponder. A transceiver includes a signal power source including electronic hardware for transmitting data signals along a physical link such as a copper wire link or fiber-optic link. The signal power source may be a laser, electronic amplifier, radio transmitter or the like. The transceiver may also include a physical layer signal reception element to receive physical layer signals. The physical layer reception element may be a photodiode, an electronic amplifier, a radio receiver, or the like.
The transceiver may include electronic hardware for decoding signals that are sent between clients into data signals, such as binary representations, readable by digital devices or hosts to which the transceiver is connected. The transceiver may also include electronic hardware for encoding signals that are sent between clients from a binary representation to a physical layer level signal that can be transmitted across a physical link. Thus, in one example, a binary representation is converted to one of a modulated electronic signal, a modulated optical signal, a modulated radio signal or another appropriate signal.
A transceiver may communicate data for the benefit of the transceiver to the connected host device. For example, a transceiver may be configured to generate digital diagnostic information by monitoring the health of the transceiver. The transceiver may then communicate information about the health of the transceiver to its connected host. This communication typically takes place on an I2C or MDIO bus for communicating between integrated circuits. As a transceiver deteriorates due to age, component failure or other reasons, the host may be aware of the deterioration using such communications received from the transceiver.
Digital diagnostics logic (also referred to herein as “digital diagnostics”) may be used to handle various tasks and to generate monitoring and operating data. These task and data may include some of the following:                Setup functions. These generally relate to the required adjustments made on a part-to-part basis in the factory to allow for variations in component characteristics such as laser diode threshold current.        Identification. This refers to general purpose memory, typically EEPROM (electrically erasable and programmable read only memory) or other nonvolatile memory. The memory may be accessible using a serial communication standard, that is used to store various information identifying the transceiver type, capability, serial number, and compatibility with various standards. While not standard, this memory may also store additional information, such as sub-component revisions and factory test data.        Eye safety and general fault detection. These functions are used to identify abnormal and potentially unsafe operating parameters and to report these to the host and/or perform laser shutdown, as appropriate.        Temperature compensation functions. For example, compensating for known temperature variations in key laser characteristics such as slope efficiency.        Monitoring functions. Monitoring various parameters related to the transceiver operating characteristics and environment. Examples of parameters that may be monitored include laser bias current, laser output power, receiver power levels, supply voltage and temperature. Ideally, these parameters are monitored and reported to, or made available to, a host device and thus to the user of the transceiver.        Power on time. The transceiver's control circuitry may keep track of the total number of hours the transceiver has been in the power on state, and report or make this time value available to a host device.        Margining. “Margining” is a mechanism that allows the end user to test the transceiver's performance at a known deviation from ideal operating conditions, generally by scaling the control signals used to drive the transceiver's active components.        Other digital signals. A host device may configure the transceiver so as to make it compatible with various requirements for the polarity and output types of digital inputs and outputs. For instance, digital inputs are used for transmitter disable and rate selection functions while outputs are used to indicate transmitter fault and loss of signal conditions. The configuration values determine the polarity of one or more of the binary input and output signals. In some transceivers, these configuration values can be used to specify the scale of one or more of the digital input or output values, for instance by specifying a scaling factor to be used in conjunction with the digital input or output value.        
The data generated by the digital diagnostics described above is generally only available to the host on which a transceiver is installed. Thus, when troubleshooting problems with individual transceivers, a user must access the host on which the transceiver is installed to discover any digital diagnostic data about a transceiver. This may cause various difficulties when the host and transceiver are located in a remote location such as on the ocean floor or in remote desert locations. Further, some applications make use of repeaters, which are transceiver pairs that simply receive an optical data stream, amplify the optical data stream, and retransmit the optical data stream. In repeater applications, the digital diagnostic data is stored on the repeater. Thus to troubleshoot the repeater, the repeater must be physically retrieved and queried for any digital diagnostic data.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some embodiments described herein may be practiced.